1. Field of the Invention
The invention relates to an apparatus for drying and superheating steam, especially for supplying steam to a turbine, with the apparatus including a horizontal cylindrical pressure tank having at least one steam inlet, a water separator that is disposed in the lower portion of the pressure tank and extends essentially over the entire length of the tank, a superheater that is disposed in the upper portion of the pressure tank, and at least one steam outlet disposed on the upper side of the tank and connected to the superheater.
2. Description of the Prior Art
An apparatus of this type is known from European Patent Application No. 0 005 225, where the two systems that are accommodated in the pressure tank, namely the water separator and the superheater, are structurally interconnected, in particular over their entire length. Due to different temperatures that exist in the two systems, the interconnection must not only be shiftable, but at the same time must also be a sealed connection in order to avoid by-pass flows. All or part of the inner surface of the pressure tank is subjected to wet steam and must for this reason be protected in an expensive manner from corrosion by being plated or by being provided with deflection plates. In the heretofore known arrangement, the water separator units are disposed parallel to the in-flowing steam. To uniformly subject the water separator units to the water in the steam, considerable resistances in the form of rectifiers must be installed, with these rectifiers causing a loss in pressure and hence a reduction of the efficiency.
Furthermore, combinations of apparatus for drying steam and for subsequent superheating are known for example from U.S. Pat. Nos. 4,103,647, 4,576,125, German Pat. No. 29 01 272 A1, U.S. Pat. No. 3,923,010 and European Patent Application No. 0 005 225 A1. For specific turbine constructions these apparatus have the drawback that the superheater, and hence the steam inlets, have to be disposed in a limited amount of space. Due to this limitation, it is necessary to have complicated steam outlet lines, resulting in pressure and heat losses.
The object of the present invention is to provide an apparatus of the type described in the inroductory portion of this disclosure, with the water separator and the superheater being independent of one another from a flow standpoint, while at the same time no greater protection against corrosion is required for the pressure tank.